Final answer:
Salivary amylase breaks down starch into smaller chains, beginning the process of starch digestion in the mouth by converting it to sugars like maltose, which may be noticed as a sweet taste when starch-rich food is chewed for a long time.
Step-by-step explanation:
Yes, salivary amylase is responsible for breaking down starch in the bread into smaller chains. This enzyme is found in the saliva produced by the salivary glands and begins the digestive process by acting on the starch that is ingested as part of the food. The chemical digestion of carbohydrates such as starch commences in the mouth with the help of salivary amylase, breaking down the long starch polymers into shorter polysaccharides and disaccharides, which then eventually become simpler sugars like glucose and maltose, the latter consisting of two glucose molecules.
When you chew food like bread that contains starch, the enzyme amylase starts working by hydrolyzing the starch into dextrins and maltose. As continues to mix the food with amylase-laden saliva. While this enzymatic activity does not completely break down all the starch in the mouth due to the short duration the food stays there, it does initiate the digestion process that will be continued by other enzymes further down in the digestive system.
When chewing something like a soda cracker for a prolonged period, typically around 5 minutes, you may notice a sweet taste developing as the amylase breaks down the starch into simple sugars that you can taste.